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MDACC Protein Array & Analysis Core (PAAC)

Overview of Services

The Protein Array and Analysis Core (PAAC) at the University of Texas MD Anderson Cancer Center Science Park provides investigators access to innovative and cutting-edge cancer research tools for the discovery and characterization of novel protein-protein interactions. This is accomplished using a state-of-the-art protein microarrayer and additional equipment that will provide biophysical analysis of protein-protein interactions. The PAAC is supported by a grant from Cancer Prevention and Research Institute of Texas (CPRIT).


Apart from identifying novel protein-protein interactions that are mediated between protein peptides and protein domains, we will provide the know-how and instrumentation to determine the strength of these protein-protein interactions. Discovering new nodes of interaction in signal transduction pathways is important because these protein networks are often deregulated in cancers. Importantly, these pathways can be targeted with drugs to inhibit the enzyme responsible for depositing the posttranslational modifications that facilitate many of these interactions. Moreover, protein-protein interactions can be directly targeted with small molecules. These findings will lay the groundwork, and identify the targets, for future cancer drug discovery projects.


Our protein-domain microarray technology facilitates the identification of proteins that interact with motifs that carry phosphorylation, methylation and acetylation modifications. This high-throughput approach allows for the rapid identification of protein-protein interactions in vitro. Additional experiments are then required to confirm that these interactions do indeed occur in vivo and in vitro.


We have developed a chip-size array of proteins that can be used to identify the “readers” of specific PTMs. We are the only research group to have such a large collection of protein domains. Thus, many researchers, who have identified PTMs that are often unique signatures of a certain cancer, send us their modified proteins in the hopes that we can identify relevant binding partners. We are now expanding this facility to not only include state-of-the-art protein domain microarrays, but also to allow the further characterization of these protein-protein interactions in cells. In addition, we will provide the instrumentation and know-how to determine the strength of these protein-protein interactions.


Services Available:

• Probe protein domain microarrays with peptides or small molecules

• Affinity measurements (Kd) for protein complexes

• Stoichiometry of protein complexes by SEC-MALS


Array Types Available:

• pY-Reader - SH2 domain array for phospho-tyrosine ligand analysis.

• pS/T-Reader - BRCT, 14-3-3, & FHA domain array for phospho-threonine and -serine ligand analysis.

• Me-Reader - Tudor, Chromo, PHD domain array for methyl-arginine and -lysine ligand analysis.

• Proline-Reader – WW and SH3 domain array for proline-rich ligand analysis.

• Sumo-Reader – An array of Sumo-interacting motifs (SIMs).

• Ac-Reader - Bromo domain array for acetylated lysine ligand analysis.

• Free C-terminal-Readers - PDZ domain array to identify free C-terminal ligands.

• Ub-Readers - Ubiquitin-Binding domains array to identify readers of ubiquitin.

• RNA-Readers - RNA-Binding domains array to identify readers of ss/ds RNA or modified RNA.


For more detailed information, please call or e-mail to set up a meeting with Core staff. Contact Mark Bedford ( for experiments involving the use of protein domain microarrays, and contact Shawn Bratton ( for experiments involving the biophysical analysis of protein complexes.


PAAC User Group Membership Request

The members of the PAAC User Group need to be Texas-based cancer researchers.


Members of the PAAC User Group benefit from a reduced fee structure and a yearly allotment of $3,000 for use in the Core. In order to receive this support, you will have to complete a “Service Request Form” and have the Project approved for funding. Applications will be vetted first by the PAAC Directors and then by the PAAC Oversight Committee.


There is the possibility that new members can be added to the current PAAC user group.


To become a new member of the PAAC user group you will need to submit a “Membership Application Form” to Mark Bedford ( Applications will be vetted by the PAAC Directors and then by the PAAC Oversight Committee (Drs. Dent, Johnson, Wood and Dalby).




Mark T. Bedford, Ph.D - Director



Shawn B. Bratton, Ph.D - Co-Director




UT MD Anderson Cancer Center    

1881 East Road, 4SCR4.1115

Houston, TX  77054

Links and Resources

  1. Protein Array & Analysis Core
  2. Dr. Mark T. Bedford Laboratory
  3. Dr. Shawn B. Bratton Laboratory


Name Role Phone Email Location
Leilei Shi, PhD
Protein Domain Microarray Staff

Service list

Search available services: View: by category alphabetically
Protein Domain Microarrays (3)
Affinity Measurements (Kd) (3)
Stoichiometry of Protein Complexes (3)
Biacore (2)